gzip and gunzip in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the gzip command do in Linux?

The gzip command compresses files to save disk space. It creates a smaller version of the file with a .gz extension.

beginner

How do you decompress a file named example.txt.gz using the command line?

You use the gunzip example.txt.gz command. It restores the original example.txt file by uncompressing it.

beginner

What happens to the original file after running gzip filename?

The original file is replaced by the compressed file filename.gz. The original file is removed to save space.

intermediate

How can you keep the original file after compressing it with gzip?

Use the -k option: gzip -k filename. This keeps the original file and creates a compressed copy.

intermediate

What is the difference between gunzip and gzip -d?

Both commands decompress files. gunzip is a shortcut for gzip -d. They work the same way.

Which command compresses a file named data.txt?

A gzip data.txt

B gunzip data.txt

C gzip -d data.txt

D gunzip -k data.txt

gzip data.txt compresses the file. The others decompress or use wrong options.

What file extension does gzip add to compressed files?

A .gz

B .tar

C .zip

D .gzip

gzip adds the .gz extension to compressed files.

How do you decompress a file named archive.gz?

A gzip archive.gz

B gunzip archive.gz

C gzip -k archive.gz

D gzip -c archive.gz

gunzip archive.gz decompresses the file to its original form.

Which option keeps the original file when compressing with gzip?

A -d

B -c

C -r

D -k

The -k option keeps the original file after compression.

What happens to the original file after running gzip filename without options?

A It stays unchanged

B It is copied to a backup folder

C It is deleted and replaced by compressed file

D It is renamed to filename.old

The original file is removed and replaced by the compressed filename.gz file.

Explain how to compress and decompress files using gzip and gunzip commands.

Think about what happens to the file before and after compression.

Describe the difference between using gunzip and gzip -d for decompression.

Consider command shortcuts and options.

Practice

1. What does the gzip command do in Linux?

easy

A. Lists files in a directory

B. Deletes a file permanently

C. Compresses a file and replaces the original with a .gz file

D. Creates a backup copy of a file

Solution

1. Step 1: Understand gzip purpose

   The gzip command compresses files to save disk space.

2. Step 2: Effect on original file

   It replaces the original file with a compressed file ending in .gz.

3. Final Answer:

   Compresses a file and replaces the original with a .gz file -> Option C

4. Quick Check:

   gzip compresses files = D [OK]

Hint: gzip compresses and replaces original file by default [OK]

Common Mistakes:

• Thinking gzip deletes files without compression
• Confusing gzip with backup commands
• Assuming gzip lists files

2. Which of the following is the correct syntax to compress a file named data.txt but keep the original file?

easy

A. gzip data.txt

B. gzip -d data.txt

C. gunzip -k data.txt

D. gzip -k data.txt

Solution

1. Step 1: Identify option to keep original

   The -k option tells gzip to keep the original file after compression.

2. Step 2: Match correct command

   gzip -k data.txt compresses and keeps the original file.

3. Final Answer:

   gzip -k data.txt -> Option D

4. Quick Check:

   Use -k to keep original file [OK]

Hint: Use -k with gzip to keep original file [OK]

Common Mistakes:

• Using gunzip instead of gzip for compression
• Using -d which is for decompression
• Not using -k and losing original file

3. What will be the output of the following commands?

gzip -k report.txt
gunzip report.txt.gz

medium

A. Only report.txt exists after commands

B. Both report.txt and report.txt.gz exist after commands

C. Original report.txt deleted, only report.txt.gz remains

D. Error because gunzip cannot decompress .gz files

Solution

1. Step 1: Analyze gzip -k report.txt

   This compresses report.txt to report.txt.gz and keeps the original report.txt file.

2. Step 2: Analyze gunzip report.txt.gz

   This decompresses report.txt.gz back to report.txt and deletes the .gz file.

3. Final Answer:

   Only report.txt exists after commands -> Option A

4. Quick Check:

   gzip -k keeps original, gunzip restores and removes .gz [OK]

Hint: gunzip removes .gz file after decompression [OK]

Common Mistakes:

• Assuming gzip deletes original with -k option
• Thinking gunzip keeps .gz file after decompression
• Confusing gzip and gunzip roles

4. You run gunzip file.txt but get an error saying "not in gzip format." What is the likely problem?

medium

A. gunzip command is misspelled

B. file.txt is not a compressed .gz file

C. file.txt is already decompressed

D. You need to use gzip instead of gunzip

Solution

1. Step 1: Understand gunzip input requirement

   gunzip expects a file compressed with gzip, usually ending with .gz.

2. Step 2: Analyze error message

   "not in gzip format" means the file is not compressed or not a .gz file.

3. Final Answer:

   file.txt is not a compressed .gz file -> Option B

4. Quick Check:

   gunzip needs .gz files [OK]

Hint: gunzip only works on gzip-compressed (.gz) files [OK]

Common Mistakes:

• Trying to decompress uncompressed files
• Confusing gzip and gunzip commands
• Ignoring file extensions

5. You have multiple log files: log1.txt, log2.txt, and log3.txt. You want to compress all of them but keep the original files. Which command will do this correctly?

hard

A. gzip -k log*.txt

B. gzip log*.txt

C. gunzip -k log*.txt

D. gzip -d log*.txt

Solution

1. Step 1: Identify command to compress multiple files

   gzip compresses files; log*.txt matches all log files.

2. Step 2: Ensure original files are kept

   The -k option keeps original files after compression.

3. Final Answer:

   gzip -k log*.txt -> Option A

4. Quick Check:

   gzip -k compresses and keeps originals [OK]

Hint: Use gzip -k with wildcard to keep originals [OK]

Common Mistakes:

• Using gunzip instead of gzip for compression
• Not using -k and losing original files
• Using -d which decompresses files